1. Field of the Invention
This invention relates generally to treatment of solid cancers. More particularly, the invention relates to a ion beam focusing lens used in conjunction with charged particle cancer therapy beam acceleration, extraction, and/or targeting methods and apparatus.
2. Discussion of the Prior Art
Cancer
A tumor is an abnormal mass of tissue. Tumors are either benign or malignant. A benign tumor grows locally, but does not spread to other parts of the body. Benign tumors cause problems because of their spread, as they press and displace normal tissues. Benign tumors are dangerous in confined places such as the skull. A malignant tumor is capable of invading other regions of the body. Metastasis is cancer spreading by invading normal tissue and spreading to distant tissues.
Cancer Treatment
Several forms of radiation therapy exist for cancer treatment including: brachytherapy, traditional electromagnetic X-ray therapy, and proton therapy.
Problem
There exists in the art of particle beam therapy of cancerous tumors a need for efficiently focusing a negative ion beam. There further exists in the art a need for generating a negative ion, extracting the negative ion, converting the negative ion into a positive ion, and injecting the positive ion into a synchrotron. There further exists in the art of particle beam treatment of cancerous tumors in the body a need for reduced synchrotron power supply requirements, reduced synchrotron size, and control of synchrotron magnetic fields. Still further, there exists a need in the art to control the charged particle cancer therapy system in terms of specified energy, intensity, and/or timing of charged particle delivery. Yet still further, there exists a need for efficient, precise, and/or accurate noninvasive, in-vivo treatment of a solid cancerous tumor with minimization of damage to surrounding healthy tissue in a patient.